PostgreSQL

Turn On the Expanded Table Formatting Mode

\x

Describe Table Structure

\d+ <SCHEMA_NAME>.<TABLE_NAME>

Estimate the Total Number of Rows

SELECT schemaname, relname, n_live_tup FROM pg_stat_all_tables WHERE relname='<TABLE_NAME>';

Check Query State

SELECT state, query FROM pg_stat_activity WHERE query LIKE '<QUERY_PATTERN>';